The blood pressure of a normal human being is found to be 120/80 mmHg. These 'numbers' represent the blood pressure at

The blood pressure reading of 120/80 mmHg represents the pressure exerted by blood against arterial walls during different phases of the cardiac cycle. The higher number (120 mmHg) is the systolic pressure, which occurs during ventricular systole or contraction [2]. During this phase, the muscular left ventricle contracts to pump blood out to the body, creating maximum pressure in the arteries [2]. The lower number (80 mmHg) is the diastolic pressure, which occurs during ventricular diastole or relaxation [1]. During this phase, the ventricles relax and fill with blood, resulting in the minimum pressure recorded in the arteries [2]. While the atria (auricles) also undergo contraction and relaxation, the standard blood pressure measurement specifically reflects the pressure changes generated by the more powerful ventricular actions [2].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Blood pressure > p. 93
2. [2] https://www.ncbi.nlm.nih.gov/books/NBK268/